The invention relates to the field of handling and storage of materials in bulk bags. In particular, the invention relates to an apparatus for pre-conditioning the material held in a bulk bag, prior to discharge, so as to break up highly compacted material.
An increasingly common method of shipping, storage, and handling commodities is the bulk bag or "super sack". The bags are sewn commonly of a synthetic fabric and generally hold up to approximately 2,000 to 2,200 pounds of product. Typically, they have four lifting loops, an inlet spout on the top which folds over after filling, and a discharge spout on the bottom which is generally folded over and tied, many times within yet another overwrap. An average super sack full of product would range from 36" square to 48" square and anywhere from 36" in height to 72" in height. The "square" is really a misnomer because although the bags are sewn square, the sides bulge significantly as product is filled into them. Many bulk bags also are fit with a liner, customarily a polyethylene tube and liners would frequently be used with products which might tend to be hydroscopic.
Bulk bags are frequently transported over long distances either by ship, truck or rail; and, they frequently stand in a warehouse for an extended period of time before the product is to be used. During transportation and storage, many products become compacted such that the material is a fairly compacted mass in the bag that will not flow from the open spout at the bottom, even after the bags have been dropped to the floor, swung against a pillar, or beat upon with baseball bats. All of these techniques have been tried at one time or another.
The bulk bag pre-conditioner of the invention is designed to replace the less sophisticated and less effective means of breaking up the material in a compacted bag so that it will flow when the bag is opened.